Artificial sundial

ABSTRACT

An artificial sundial formed of a rotatable motor having a shaft which extends through a planar translucent member. A time indicator is positioned adjacent the inner surface of the planar member and is rotatable with the motor shaft. A shadow effect member is secured to the motor shaft and has a portion positioned adjacent the outer surface of the planar member. The time indicator and the shadow effect member rotate in unison with the shaft and produce a visual indication of time.

Unlted States Patent 1 1 3,832,842

Parker Sept. 3, 1974 ARTIFICIAL SUNDIAL Primary Examiner-Edith Simmons Jackmon [76] Inventor 2:1 gfit gg ggg 532 Attorney, Agent, or Firm-Nilsson, Robbins Bissell,

Dalgarn & Berliner [22] Filed: July 5, 1973 [21] Appl. No.: 376,844 [57] ABSTRACT An artificial sundial formed of a rotatable motor having a shaft which extends through a planar translucent member. A time indicator is positioned adjacent the inner surface of the planar member and is rotatable with the motor shaft. A shadow effect member is secured to the motor shaft and has a portion positioned adjacent the outer surface of the planar member. The time indicator and the shadow effect member rotate in unison with the shaft and produce a visual indication of time.

8 Claims, 3 Drawing Figures ARTIFICIAL SUNDIAL FIELD OF THE INVENTION BACKGROUND AND SUMMARY OF THE INVENTION The oldest known device for the measurement of time is the sundial. A sundial operates on the principle that the shadow of an object will move from one side of the object to the other as the sun moves from the east to west during the day. Typically, the sundial consists of a plane (dial face) and a gnomon (style). The dial face is divided into time intervals such as hours and portions of hours. The gnomon is a flat piece of metal set in the center of the dial which points toward the North Pole in the Northern Hemisphere and the South Pole in the Southern Hemisphere. The upper edge of the gnomon slants upwardsfrom the dial face at an angle equal to the latitude of the location of the sundial.

The present invention utilizes the basic aesthetic principles of a sundial to provide a time indicator which is driven by a conventional clock motor. A planar member which acts as the dial faceof the artificial sundial contains time intervals thereon. An indicator is provided beneath the surface of the sundial for giving a visual indication of the time. A light source or sources can be'provided adjacent the interior surface of the dial BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an artificial sundial;

FIG. 2 is a cross-sectioned view of the sundial taken along the line 2--2 of FIG. 1; and

FIG. 3 is a partial cross-sectional view of the sundial taken along the line 3-3 of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 2, the artificial sundial is shown in greater detail. The shadow maker 22 is formed the shape of a right triangular member and contains a base edge 24 adjacent the face 16, an altitude I Referring nowto the drawings, thereis shown in FIG.

1 an artificial sundial l2 constructed in accordance with the principles of the invention. The artificial sundial 12 is shown mounted on a base 14. However, it should be understood that the sundial could be mounted on a desk or of any other type of support, the

.base 14 merely being illustrative of the type of stand available for use with the sundial of the present invention.

The artificial sundial 12 contains a face 16 having numerals 18 such as Roman numerals, positioned around its periphery. A simulated shadow maker 22 extends in a plane perpendicular to the plane of the face 16 and is centrally positioned thereon.

edge 26 and a hypotenuse edge 28. The simulated shadow-maker corresponds to the gnomon which typically stands in the center of a true sundial.

The sundial 12 contains a clock motor 32 having an hour-hand shaft 34 extending therefrom. The clock motor 32 is connected by means of a conventional two wire-line 38 to a 110 volt A.C. source.

The clock motor 32 is secured to the outer surface of an oval shaped dish 42 by means of a plurality of bolts 44. The bolts 44 fasten a motor mounting plate 46 to the dish 42 as they are threaded into stems 47 extending from the dish 42. A central aperture 48 in the dish 42 enables the hour-hand shaft 34 to extend through to the interior of the oval shaped dish 42.

The oval shaped dish 42 further contains a recessed flange 52 formed around its periphery 54. The flange 52 is of sufficient size so that the sundial face 16 can be recessed therein and positioned flush with the periphery 54 of the dish 42.

A plurality of conventional lamps 56 are positioned equidistant around the inner surface of the dish 42 and are connected by wires 58 through a switch 60 to the 110 volt A.C. source. By using multiple lamps the clockshaft and the like shadows are eliminated. The free end of the hour-hand shaft 34 is connected to a drive shaft 62 through a slip coupling 64. The slip coupling 64 enables the drive shaft 62 to be rotated with respect to the hour-hand shaft 34 as will be explained hereinafter. The drive shaft 62 extends through an opening 66 in the center of the face 16. The simulated shadow-maker 22 has 'a bore 68 in its base edge 24, which is positioned over a reduced diameter end 70 of the drive shaft 62 extending through the clock face 16. The simulated shadow-maker is then secured to the drive shaft by means of a set screw 72 which extends into the bore 68, thereby enabling the shadow-maker to rotate-with the shaft.

A time indicator 74 is positioned in a plane parallel to the side of the face 16 adjacent the dish 42. As can be seen in FIG. 3, indicator 74 contains a pointed edge 76 which is adjacent and below the numerals 18. The other end of the time indicator 74 is fitted into a slot 77 in the drive shaft 62. The time indicator 74 thus rotates with the shaft 62 and simulated shadow-maker 22.

The time indicator 74 is a relatively thin member. A pivot member 78 is secured to the time indicator 74 at the center of gravity 82 of the time indicator 74. The time indicator 74 tends to remain in a plane parallelto theface 16 The pivot member 78 is also secured by a second pivot point 84 to the shaft 62. The pivot member 78 extends between the first and second pivot points 82 and 84, forming an angle with the time indicator 74. The pivot member 78 further contains a counter-balance section 86. The counter-balance section 86 extends from the drive shaft 62 in a plane parallel to the pivot member 78 and counter-balances the pivot member by means of a weight 88.

In normal operation, the simulated shadow-maker 22 is grasped and rotated to a position so that it and the time indicator 74 provide a desired offset with respect to each other (shown parallel in FIG. 2 only for illustration; usually about 60-90). The time indicator 74 is positioned at the correct time of day. Due to the slip coupling 64, the drive shaft 62 can be rotated with respect to thehour-hand shaft 34. When the line 38 is connected to the 1 volt source, the clock motor causesthe drive shaft 62 to rotate through the slip coupling 64 and an indication of the time is provided by the time indicator 74 through the face 16. Typically, the face 16 can be made of glass, plastic or other translucent-type material. I

When the lamp switch 60 is closed, the lamps 56 illuminate the interiorof the oval shaped dish and light is reflectedfrom the surface of the dish upwardly toward the face 16. The light rays from the lamps 56 are blocked by the time indicator 74 thus providing a darkened indicator portion on the face 16. Note, however, that even with the lamps out, the time indicator 74 is still visible beneath the translucent clock face.

The artificial sundial has been illustrated with only an hour-hand in the manner similar to conventional sundials. However, it should be understood .that a minute hand or even a second hand could be added as well together with simulated shadow-maker although such would detract from the conventional sundial appearance. Additionally, instead of lamps, a white background could be provided beneath the sundial face which would provide sufficient shadow effect. Moreover, the clock motor could be battery-operated so as to eliminate the need for wires connected to the 110 volt source.

I claim:

1. An artificial sundial comprising a planar member having an interior surface and an exterior surface;

a rotatable motorhaving a shaft extension extending member intermediate said light source and said planar member interior surface, and rotatable with said motor shaft; and E a simulated shadow-maker a portion thereof positioned adjacent said exterior surface of said planar member for providing an'artificial shaodw effect with respect to said indicator means.

2. An artificial sundial in accordance with claim 1 wherein said simulated shadow maker is secured to said shaft,.said time indicator means and said simulated shadow maker being rotatable in unison with said shaft.

3. An artificial sundial in accordance with claim 2 wherein said time indicator means is movable in a plane parallel to said planar member.

4. An artificial sundial in accordance with claim 2 wherein said simulated shadow maker is mounted in a plane perpendicular to said planar member.

5. An artificial sundial in accordance with claim 2 wherein said planar member is made of translucent material.

6. An artificial sundial in accordance with claim 5 wherein said artificial light source has its light energy directed toward said translucent planar member and passes through said planar member in a direction extending from said interior surface towards said exterior surface.

7. An artificial sundial in accordance with claim 5 wherein said translucent planar member contains indicia indicative of time on its exterior surface.

8. An artificial sundial in accordance with claim 3 wherein said time indicator means is pivotably secured to said shaft for maintaining said shaft in a plane parallel to said planar member. 

1. An artificial sundial comprising a planar member having an interior surface and an exterior surface; a rotatable motor having a shaft extension extending through said planar member; an artificial light source; time indicator means positioned adjacent said planar member intermediate said light source and said planar member interior surface, and rotatable with said motor shaft; and a simulated shadow-maker a portion thereof positioned adjacent said exterior surface of said planar member for providing an artificial shaodw effect with respect to said indicator means.
 2. An artificial sundial in accordance with claim 1 wherein said simulated shadow maker is secured to said shaft, said time indicator means and said simulated shadow maker being rotatable in unison with said shaft.
 3. An artificial sundial in accordance with claim 2 wherein said time indicator means is movable in a plane parallel to said planar member.
 4. An artificial sundial in accordance with claim 2 wherein said simulated shadow maker is mounted in a plane perpendicular to said planar member.
 5. An artificial sundial in accordance with claim 2 wherein said planar member is made of translucent material.
 6. An artificial sundial in accordance with claim 5 wherein said artificial light source has its light energy directed toward said translucent planar member and passes through said planar member in a direction extending from said interior surface towards said exterior surface.
 7. An artificial sundial in accordance with claim 5 wherein said translucent planar member contains indicia indicative of time on its exterior surface.
 8. An artificial sundial in accordance with claim 3 wherein said time indicator means is pivotably secured to said shaft for maintaining said shaft in a plane parallel to said planar member. 